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61.
Aoshio-hypoxic water which can be distinguished from surrounding coastal water by its milky blue-green color-is often observed at
the head of Tokyo Bay when coastal upwelling of sulfidic bottom water occurs during summer and early autumn. Optical properties
and the biological-chemical composition of suspended matter in theaoshio water were investigated using nearby “normal” coastal water as a reference.
Suspended matter in theaoshio water contributed to the large beam-attenuation coefficient and also to the strong upward radiance with maximal intensity
around 550 nm as a result of the scattering process. No significant difference in bacterial density was observed between samples
ofaoshio water and reference coastal water. The low chlorophylls concentration inaoshio water samples indicates that biological pigments may not play a dominant role in the color of theaoshio events.
The suspended particles inaoshio water samples had much higher contents of sulfur and manganese and a lower silicon content than those in reference coastal
water samples. The colloidal elemental sulfur and manganese-rich particles identified in theaoshio water appear to be oxidation products of dissolved sulfide and manganese (II) in the anoxic water.
On the basis of these findings, it may be concluded that there is a high probability that elemental sulfur and manganese-rich
particles are responsible for the color and turbidity inaoshio. 相似文献
62.
The Japanese government is committed to resuming sustainable commercial whaling, both on the high seas and along the Japanese coastline. To this end scientific whaling programs are supported with public money and the byproducts of the catch are distributed to the public and utilized in a variety of ways. Here we review the policies which govern how these byproducts are disseminated within Japan, as well as how the population as a whole makes use of whale resources. Possibilities for the future, if and when the international moratorium on commercial whaling ends, are also discussed. 相似文献
63.
Masahiro Endoh 《Journal of Oceanography》1977,33(1):30-37
Simple numerical experiments on two-dimensional coastal upwelling are made with emphasis on the role of non-geostrophic solenoidal field of density in the formation of double-celled circulation and multi-celled density front. Geometry of shelf and slope is not taken into account. Existence of poleward undercurrent presumably caused by the longshore variation of the large scale pressure field is also suppressed for the sake of simplicity.The results are, (1) double-celled circulation revealed in the present experiment is closely related with the internal frictional layer, where the horizontal density gradient balances with the vertical gradient of the longshore velocity and the vertical diffusion of the vorticity. (2) density front formed by the emergence of the pycnocline to the sea surface is successively advected offshoreward by the Ekman transport. (3) the pycnocline intersecting the sea surface forms the density front which is nearly vertical on account of the small scale convection. The surface currents converge at the front and construct an anti-clockwise circulation (viewed from the lee side). (4) small coefficient of eddy viscosity and strong wind stress lead the Ekman transport unstable and form a multi-celled structure in the frontal region. 相似文献
64.
65.
Toshiyuki Hirano 《Journal of Oceanography》1986,42(6):490-501
This is a review of the study on the oceanic environments relating to the marine living resources carried out since 1947, during more than 35 years which are the period of the authors oceanographic research life for fisheries. Its content consists of describing the outlines of, (1) the oceanographic study of the Subarctic Region of the Northwestern Pacific as the salmon living waters, (2) the study on dilution processes of the effluent in the coastal waters in relation to marine pollution, (3) the oceanographic study on transportation and diffusion of fish eggs and larvae in relation to the recruitment of living resources and (4) the study on forecasting of the fisheries and oceanographic conditions, and a short note on direction of fisheries oceanography expected to be studied in the future. 相似文献
66.
The stability constants for sulfate, chloride and hydroxide ions with cerium (III) in the solution at ionic strength of 0.67 have been determined by cation exchange method, the values of
1 and
2 for sulfate complexes of cerium being 40±13 and 453±140, respectively and those for chloride complexes being 1.28±0.23 and 0.56±0.076, respectively. The values of
1,
2 and
3 for hydroxide complexes of cerium were (4.5±0.9)×107, (3.3±0.7)×1014 and (1.8±0.7)×1023, respectively.Using the above constants the ratios of individual chemical species of144Ce were calculated in a solution at ionic strength of 0.67 containing sulfate and chloride ions approximately the same as in seawater of 35 %. The result of calculation indicates that the dominant species of144Ce in this solution is Ce(OH)3
0 at pH 8. 相似文献
67.
68.
Masato Naruse Tetsuya Ito Yutaro Sekimoto Hiroyuki Toba Naohisa Satou Masahiro Sugimoto Wenlei Shan Yoshizou Iizuka Toshiaki Kamba Mamoru Kamikura Yasutaka Serizawa 《Experimental Astronomy》2009,24(1-3):89-107
We have developed a near-field vector beam measurement system covering the range of frequencies from 385 to 500 GHz. The measurement set-up is capable of measurements with dynamic range exceeding 50 dB and amplitude and phase stability respectively of 0.1 dB/h and 1 degree/5 min at room temperature. Beam patterns of the ALMA band 8 corrugated horns and receiver optics block were measured at room temperature and lately compared with physical optics calculations obtained in the far-field. Both co-polar and cross-polar beam patterns of a qualification model of the ALMA band 8 cartridge cooled in a cartridge-test-cryostat have also been measured in the near-field as a detector of a submillimeter vector network analyzer. The measurements presented in this work refer to the lowest, middle and upper frequencies of band 8. The comparisons between software model and experimental measurements at these frequencies show good agreement down to ?30 dB for the main polarization component. The cross-polarization level of the beam propagating through the receiver optics block was also characterized. We found that a cross-polarization level better than ?28 dB can be achieved at all measured frequencies. The measured beam pattern of this receiver corresponds to efficiency of greater than 92% at the sub reflector (diameter of 750 mm) of the ALMA 12 m optics. 相似文献
69.
Ryoei Kikuchi Makoto Takada Keita Hifumi Keiji Yoshimura Toru Ozeki Takashi Kimoto Masahiro Kajikawa Nobuaki Ogawa 《Atmospheric Research》2009,94(3):501-509
It is well known that sea-salt aerosols in particulate matter (PM) react with acids such as H2SO4 and HNO3 during transportation and thereby lose chloride ions (Cl-loss). The PM and fog were sampled concurrently at different altitudes in the Hachimantai mountain range, northern Japan. The PM and fog sampled at different altitudes had nearly identical properties for the ion components. However, the PM was in a Cl-depleted state (more than 80% of all samples), but the fog water was not in so Cl-depleted state (less than 29%). As a result, it could be explained that this phenomenon caused because the fog droplets took up the gaseous state HCl other than sea-salt PM. After all Cl- in the fog water recovered and was rather rich compared with the sea-salt or the PM by the uptake of the gaseous state HCl. Moreover, it was found that for PMcoarse(2.5 < D < 10), 86% of the acid (H2SO4 and HNO3) was consumed for Cl-loss reactions and/or for dissolution of Ca and Mg in soil particles. 相似文献
70.
Atsushi Okamoto Hanae Saishu Nobuo Hirano Noriyoshi Tsuchiya 《Geochimica et cosmochimica acta》2010,74(13):3692-3706
We conducted hydrothermal flow-through experiments at 430 °C and 31 MPa to investigate the mechanism of silica precipitation on granite under crustal conditions. Two experiments were performed using different input solutions: a single-component Si solution, and a multi-component solution with minor Al, Na, and K. The degree of supersaturation with respect to quartz, Ω = CSi/CSi,Qtz,eq, where CSi and CSi,Qtz,eq indicate Si concentration in solutions and the solubility of quartz within water, respectively, decreased from 3-3.5 to <1.1 along the flow path. A variety of silica minerals formed during the experiments (opal-A, opal-C, chalcedony, and quartz), and their occurrences and modal abundances changed in response to Ω and the presence of additives in the solution.For near-equilibrium solutions (Ω < ∼1.2), silica precipitation occurred in a simple way in both experiments, being restricted to overgrowths on pre-existing quartz surfaces in the granite. At higher saturation levels (Ω > ∼1.2), silica minerals were deposited on other surfaces in addition to quartz. In the single-component experiment, the dominant silica minerals changed in the order of opal-A → opal-C → quartz with decreasing Si concentration along the flow path. In contrast, in the multi-component experiment, quartz and minor chalcedony formed throughout the entire reaction vessel. This finding indicates that impurities (Na, K, and Al) in the solutions inhibited the precipitation of opal and enhanced the direct nucleation of quartz. The systematic appearance of metastable silica minerals were examined by nucleation processes and macroscopic precipitation kinetics. Our experimental results indicate that different precipitation mechanisms yield contrasting textures, which in turn suggests that vein textures can be used as indicators of solution chemistry within the fracture. 相似文献